The upper airflow (look at the little arrows along the coast) is swinging around to start bringing warmer more moist air into Oregon. A frontal system is approaching the coast of California (see last frame of animation). It will move in and spread moisture northward over us. That sets up a situation that could produce some nasty weather conditions, especially when that air mass first gets here.
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Advisories: A FREEZE WARNING IS IN EFFECT FROM 11 PM TONIGHT THROUGH 9 AM FRIDAY FOR THE SOUTH OREGON COAST. A WINTER STORM WATCH IS IN EFFECT FROM FRIDAY EVENING THROUGH SATURDAY AFTERNOON FOR THE NORTHERN COAST RANGE. ANOTHER IS IN EFFECT FROM FRIDAY AFTERNOON THROUGH LATE FRIDAY NIGHT FOR THE CENTRAL COAST RANGE, FROM FRIDAY AFTERNOON THROUGH SATURDAY AFTERNOON FOR THE FOOTHILLS OF THE NORTH CASCADES.. A WINTER STORM WATCH IS IN EFFECT FOR TH I-5 CORRIDOR FROM EUGENE NORTH FROM THIS EVENING THROUGH SATURDAY AFTERNOON..
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For the Willamette Valley: Mostly clear overnight tonight low 11-13. A WINTER STORM WATCH IS IN EFFECT FROM FRIDAY AFTERNOON THROUGH LATE FRIDAY NIGHT. Friday some AM clouds, then mostly cloudy in the afternoon with a slight (20%) chance of rain, freezing rain, and snow in the afternoon high 30-34, mostly cloudy at night with a (50%) chance of rain and light freezing rain low 17-20. AM rain and light freezing rain likely (60%) Saturday high 33-36 then rain likely (60%) Saturday night and it will be warmer low 33-35. Mostly cloudy Sunday with a (50%) chance of rain high 42-44. Mostly cloudy with a (50%) chance of rain Sunday night lows 35-37. Mostly cloudy with rain likely (60-70%) Monday night through Wednesday highs warming from 44-50 lows 34-39. Rain will be likely (60%) Wednesday night and a (50%) chance of showers Thursday low 36-39 high near 50.
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For the Umpqua Basin: Tonight partly cloudy and becoming mostly cloudy low 23-26. Friday mostly cloudy with a slight (20%) chance of snow in the morning (snow level 1,500′ in the afternoon) then snow likely (60%) in the afternoon, no accumulation expected high 36-40. Rain (70%) Friday night (snow level 3,500′) and a bit warmer low 36-39. Rain (80% chance) Saturday and rain likely (60%) Saturday night (snow level 3,000′) high 39-43 low 35-39. Rain and and snow will be likely Sunday and snow showers likely Sunday night high 40-43 low 34-36. Rain will be likely (60%) Monday through Wednesday night highs warming 45-50 lows near 40. Thursday will be cloudy with a good (50%) chance of rain high in the low 50s.
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Forecast for the South Coast: Partly cloudy this evening, then mostly cloudy at night low 28-30. A FREEZE WARNING IS IN EFFECT FROM 11 PM TONIGHT UNTIL 9 AM FRIDAY. Mostly cloudy Friday with a slight (20%) chance of rain in the AM at the beaches chance of rain and snow inland rain likely (60%) in the afternoon high 47. Cloudy with rain Friday night low near 39-41. Rain (80%) Saturday and Saturday night high 48-50 low 44. Rain likely (60%) Sunday with showers (70%) Sunday night high 46-48 low near 40. Rain (70-80%) Monday through Wednesday night highs warming to the low to mid 50s lows low to mid 40s Thursday rain likely (60%) high 53-56.
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Advisory for the Cascade foothills of Lane County: A WINTER STORM WATCH IS IN EFFECT FROM FRIDAY AFTERNOON THROUGH SATURDAY AFTERNOON.
For the Cascades: The free air freezing level will be at the surface tonight going to 3,000′ in the afternoon Friday and then a snow level of 3,000′ Friday night, then a snow level of 3,500′ Saturday and Saturday night, down to the surface Sunday, 2,500′ Sunday night. Monday the snow level will back up to 3,000′ ,Monday night 4,000′, and 5,000′ Tuesday, and 4,500′ Tuesday night and Wednesday . The snow level will rise to 5,000′ Wednesday night and Thursday.
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The weekly quiz question was correctly answered so the next quiz will start next Monday. To see the winner go back to the post where it was announced. A reminder for this week’s winner Tim to contact me about his prize.